Manufacturing method of an iron-type golf club head

Abstract

A manufacturing method of an iron-type golf club head has acts of: forming a blank for an iron-type club head with a raw material selected from the group of medium-carbon and low-carbon steel, wherein the blank has a striking face integrally-formed; heating a center of the striking face on the blank to a predetermined quenching temperature; quenching the blank to cool down the blank rapidly to form a hardened layer, wherein a hardness of the striking face gradually decreases radially from the center to a periphery of the striking face; machining the striking face to form multiple grooves, and surface treating the blank to accomplish the iron-type golf club head. Therefore, the iron-type golf club head has a softer head body and a harder striking face to have the inclined angles of the hosels easily adjusted, as well as high resistance of the striking face.

1 . A manufacturing method of an iron-type golf club head comprising acts of:
 (a) forming a blank for an iron-type club head with a raw material selected from the group of medium-carbon steel and low-carbon steel, wherein the blank has a striking face integrally-formed;   (b) heating a center of the striking face on the blank to a predetermined quenching temperature;   (c) quenching the blank to cool down the blank rapidly to form a hardened layer, wherein a hardness of the striking face gradually decreases radially from the center to a periphery of the striking face;   (d) machining the striking face to form multiple grooves; and   (e) surface treating the blank to accomplish the iron-type golf club head.   
     
     
         2 . The manufacturing method as claimed in  claim 1 , wherein
 in step (b), the heating method is selected from the group of flame heating, medium frequency induction heating, high frequency induction heating and electrical heating; and   in step (b), the predetermined quenching temperature is decided by the carbon content of the raw material for the blank and is lower than the transformation temperature of the raw material for the blank.   
     
     
         3 . The manufacturing method as claimed in  claim 2 , wherein step (b) further comprises an act of measuring the temperature of the center of the striking face with a thermometer. 
     
     
         4 . The manufacturing method as claimed in  claim 1 , wherein step (c) further comprises an act of putting the blank into water or oil at a temperature from 5° C. to 80° C. when the striking face is heated to the predetermined quenching temperature to form the hardened layer with a depth from 3 mm to 20 mm. 
     
     
         5 . The manufacturing method as claimed in  claim 2 , wherein step (c) further comprises an act of putting the blank into water or oil at a temperature from 5° C. to 80° C. when the striking face is heated to the predetermined quenching temperature to form the hardened layer with a depth from 3 mm to 20 mm. 
     
     
         6 . The manufacturing method as claimed in  claim 3 , wherein step (c) further comprises an act of putting the blank into water or oil at a temperature from 5° C. to 80° C. when the striking face is heated to the predetermined quenching temperature to form the hardened layer with a depth from 3 mm to 20 mm. 
     
     
         7 . The manufacturing method as claimed in  claim 4 , wherein in step (a), the blank is formed by precision casting. 
     
     
         8 . The manufacturing method as claimed in  claim 5 , wherein in step (a), the blank is formed by precision casting. 
     
     
         9 . The manufacturing method as claimed in  claim 6 , wherein in step (a), the blank is formed by precision casting. 
     
     
         10 . The manufacturing method as claimed in  claim 4 , wherein in step (a), the blank is formed by forging. 
     
     
         11 . The manufacturing method as claimed in  claim 5 , wherein in step (a), the blank is formed by forging. 
     
     
         12 . The manufacturing method as claimed in  claim 6 , wherein in step (a), the blank is formed by forging.